"I respect the people's right to demonstrate, but I wish that they weren't demonstrating in a violent manner," Welter said.

He added that some in the crowd did not appear to be residents of Anaheim. "This concerns me greatly."

Shortly before 9 p.m. Tuesday, law enforcement officers in Anaheim issued a dispersal order to protesters at the intersection of Anaheim and Broadway.

One officer used a megaphone to declare an unlawful assembly and shouted to demonstrators to leave the area: "You must disperse ... if you do not, you will be arrested."

At least two arrests have been made, authorities said, and an Orange County Register reporter was injured by a thrown rock.

Just after 9 p.m., authorities fired nonlethal projectiles into the crowd, scattering many of the demonstrators.

The crowd quickly moved toward a corner gas station, where people pounded on pumps as others chanted "Si se puede." Some set off firecrackers in the lot as people ran away. At one point a black police truck was struck by an object.